A deployment plan is an XML document and it is used to define an application’s deployment configuration for a specific WebLogic Server environment which includes development, test, or production etc. The most commonly used application packages are Java Archive (jar) , Web Archive (war) or Enterprise Archive (ear) in JavaEE world . They includes the application servers to deploy JavaEE application using above packages, standard rules (based on the archive option) needs to be followed to create folder structure to keep application specific java classes, dependent libraries or deployment descriptors etc.
Most commonly used deployment descriptor files are Web Archive, Java Archive, Enterprise Archive etc. Developers describe their application information’s and provides instructions to application server to deploy them accordingly through deployment descriptors.
All Java EE application servers provides an implementation to JSR-88. We can change our application behavior at runtime without modifying any deployment descriptor and rebuilding our application package, which is called as a “Deployment Plan”. For example, EJB is bundled in Java Archive (jar), deployment descriptor are supplied under META-INF/ejb-jar.xml and META-INF/weblogic-ejb-jar.xml. Application is deployed as an Enterprise Archive (ear).
Deployment plan working include many steps to reach the finalconfiguring. Steps include Prepare plan XML file and give it a name. Also Plan XML file which should contain the informations we want to override at runtime. In our case, its a ejb-class name. Deployment plan is nothing but a special XML file which can be prepared to instruct application server to use along with the package archive .Here the informations in plan xml file overrides one specified in deployment descriptor. Next steps include Save plan xml file at some location on the same machine where application server is running.
Then Log into administration console — -> Deployment. After that Click on “Change Path” button and navigate to the file where you have saved plan.xml file. Select redeploy and finish and now, application server will redeploy the application using “Deployment Plan” we specified. Then we will see application is deployed successfully. Just to make sure, what is the EJB class being used, click on EJB Module and Configuration for the final configuration.